Lignin-based Polymers Research Articles

Improving the performance of bentonite-free water-based mud with lignin-based biopolymer

Various drilling problems are associated with bentonite utilization in water-based muds, including formation damage, reduced production rate and overall cost. Various alternative solutions in terms of bio and synthethic based polymers have been tested to replace bentonite. However, due to their higher costs and availability, industry is looking for ecofriendly alternatives to overcome this issue. This work aims to utilize a lignin-based polymer (BioDrill FM400) for the formulation of bentonite-free mud blends with various dosages. The rheological and filtration properties were examined using the API standard procedures both at standard and high-temperature conditions. Seven mud blends with various dosages of the additive (0-12 ppb) were prepared, and mud’s plastic viscosity, yield point and gel strength were measured using viscometer. Similarly, mud filtration characteristics were assessed both with API and HPHT filterpress. Three types of rock disks (0.25" thick x 2.5" in diameter) were utilized to mimic the actual pore plugging mechanism. The rheological findings showed that the PV, YP and GS were significantly improved. On the other hand, the filtrate volume and filtercake thickness were reduced by 63 and 42% for the Bandera Brown disk sample. The current formulation is useful in drilling the payzone section of the wellbore.

Lignin Upconversion by Functionalization and Network Formation.

Lignin, a complex and abundant biopolymer derived from plant cell walls, has emerged as a promising feedstock for sustainable material development. Due to the high abundance of phenylpropanoid units, aromatic rings, and hydroxyl groups, lignin is an ideal candidate for being explored in various material applications. Therefore, the demand on lignin valorization for development of value-added products is significantly increasing. This mini-review provides an overview of lignin upconversion, focusing on its functionalization through chemical and enzymatic routes, and its application in lignin-based polymer resins, hydrogels, and nanomaterials. The functionalization of lignin molecules with various chemical groups offers tailored properties and increased compatibility with other materials, expanding its potential applications. Additionally, the formation of lignin-based networks, either through cross-linking or blending with polymers, generates novel materials with improved mechanical, thermal, and barrier properties. However, challenges remain in optimizing functionalization techniques, preserving the innate complexity of lignin, and achieving scalability for industrial implementation. As lignin's potential continues to be unlocked, it is poised to contribute significantly to the shift towards more eco-friendly and resource-efficient industries.

Coating of a lignin-based polymer with ceramic micropowders

This paper examines the behavior of Arboblend V2 Nature biopolymer samples coated with three distinct ceramic powders: Amdry 6420 (Cr2O3), Metco 143 (ZrO2 18TiO2 10Y2O3), and Metco 136F (Cr2O3-xSiO2-yTiO2). Atmospheric Plasma Spray (APS) method were used to deposit the coating onto the polymeric substrate, which was obtained by injection molding. Several characteristics of the coated samples, as thermal behavior, roughness, as well as structural and morphological aspects, were evaluated during the investigation. The surface analysis of the samples demonstrated a uniform deposition for the ZrO2 18TiO3 10Y2O3 layer, but a less uniform deposition for the coatings containing ceramic micro-particles of chromium (III) oxides. The thermal research revealed the material's structural resilience. Regarding Atomic Force Microscopy examination, it highlighted the roughness of the coated surfaces and also the good adhesion of the microparticles on the biopolymer substrate.

Layer-by-layer assembly of sustainable lignin-based coatings for food packaging applications

Packaging plays a critical role in ensuring food safety and shelf life by protecting against e.g., moisture, gases, and light. Polyethylene (PE) is widely used in food packaging, but it is mainly produced from non-renewable resources and it is an inefficient oxygen and light barrier. In this study, the layer-by-layer (LbL) assembly of a sustainably produced lignin-based polymer (EH) with polyethylenimine (PEI) or chitosan (CH) was used to fabricate (partially or fully) bio-based coatings with the aim of improving barrier properties of PE films. The charge density of EH was calculated using a polyelectrolyte titration method and the hydrodynamic diameters of EH, PEI and CH were determined by Dynamic Light Scattering (DLS). LbL assembly was monitored in situ via Quartz Crystal Microbalance with Dissipation (QCM-D) and Stagnation Point Adsorption Reflectometry (SPAR). PE films were coated with a variable number of PEI/EH or CH/EH bilayers (BL) using an immersive LbL assembly method. Coated films were studied in terms of light-blocking ability, wettability, thermal behaviour, surface structure, as well as oxygen and water vapor barrier properties. QCM-D and SPAR data showed a stepwise multilayer formation and strong interactions between the oppositely charged polymers, with PEI/EH coating having a greater amount of deposited polymer compared to CH/EH coating at the same number of BL. Overall, light barrier properties and wettability of the coated films increased with the number of deposited bilayers. Coated PE films maintained the overall thermal behaviour of PE. A number of BL of 20 was found to be the most promising based on the studied properties. Selected samples showed improved oxygen and water vapor barrier properties, with PEI/EH coating performing better than CH/EH coating. Taken altogether, we demonstrated that a novel and sustainable lignin-based polymer can be combined with PEI or CH to fabricate (partially or fully) bio-based coatings for food packaging.

A pH-Sensitive Lignin-Based Material for Sustained Release of 8-Hydroxyquinoline.

The fabrication of pH-sensitive lignin-based materials has received considerable attention in various fields, such as biomass refining, pharmaceuticals, and detecting techniques. However, the pH-sensitive mechanism of these materials is usually depending on the hydroxyl or carboxyl content in the lignin structure, which hinders the further development of these smart materials. Here, a pH-sensitive lignin-based polymer with a novel pH-sensitive mechanism was constructed by establishing ester bonds between lignin and the active molecular 8-hydroxyquinoline (8HQ). The structure of the produced pH-sensitive lignin-based polymer was comprehensively characterized. The substituted degree of 8HQ was tested up to 46.6% sensitivity, and the sustained release performance of 8HQ was confirmed by the dialysis method, the sensitivity of which was found to be 60 times slower compared with the physical mixed sample. Moreover, the obtained pH-sensitive lignin-based polymer showed an excellent pH sensitivity, and the released amount of 8HQ under an alkaline condition (pH = 8) was obviously higher than that under an acidic condition (pH = 3 and 5). This work provides a new paradigm for the high-value utilization of lignin and a theory guidance for the fabrication of novel pH-sensitive lignin-based polymers.

The Biomodified Lignin Platform: A Review.

A reliance on fossil fuel has led to the increased emission of greenhouse gases (GHGs). The excessive consumption of raw materials today makes the search for sustainable resources more pressing than ever. Technical lignins are mainly used in low-value applications such as heat and electricity generation. Green enzyme-based modifications of technical lignin have generated a number of functional lignin-based polymers, fillers, coatings, and many other applications and materials. These bio-modified technical lignins often display similar properties in terms of their durability and elasticity as fossil-based materials while also being biodegradable. Therefore, it is possible to replace a wide range of environmentally damaging materials with lignin-based ones. By researching publications from the last 20 years focusing on the latest findings utilizing databases, a comprehensive collection on this topic was crafted. This review summarizes the recent progress made in enzymatically modifying technical lignins utilizing laccases, peroxidases, and lipases. The underlying enzymatic reaction mechanisms and processes are being elucidated and the application possibilities discussed. In addition, the environmental assessment of novel technical lignin-based products as well as the developments, opportunities, and challenges are highlighted.

Lignin-based polymer with high phenolic hydroxyl group content prepared by the alkyl chain bridging method and applied as a dopant of PEDOT

Lignin-based polymer with high phenolic hydroxyl group content prepared by the alkyl chain bridging method and applied as a dopant of PEDOT

Investigation of humidity-heat aging resistance of a soy protein adhesive fabricated by soybean meal and lignin-based polymer

The excellent bonding strength and durability of bio-based protein adhesives are key to expand their practical applications in wood industry. The durability of adhesive is affected by environmental exposure such as temperature and humidity, but there are limited reports about the durability of the protein adhesive. Herein, a soybean meal (SM)-based adhesive modified by epoxy polymer of lignin (EPL) was prepared and then treated under high humidity-heat aging conditions (90 ± 5% RH and 50 ± 2 °C) for 1200 h to assess the durability of adhesive. The results showed that the main structure and thermal stability properties of SM/EPL adhesive were affected by the humidity-heat aging treatment, and the thermal stability of adhesive remained good. The wet shear strength of the adhesive decreased with the aging time, which was because that the hydrolysis, oxidation, and hydrogen bonds dissociation of the adhesive reduced the cross-linking density and intermolecular force in the adhesive system. Furthermore, there was no mildew occurred on the SM/EPL adhesive, and the bonding strength of SM/EPL adhesive still met the interior-use plywood requirement (≥0.7 MPa) after being treated for 1200 h. This study demonstrates that the wood products fabricated by SM/EPL adhesive are durable in high humidity-heat environment.

Waste lignin-based cationic flocculants treating dyeing wastewater: Fabrication, performance, and mechanism

Lignin is often considered to be a complex polymeric structural material with excellent scalability. Reduced pressure distillation, a novel effective way, was proposed to recover reusable waste lignin from textile degumming black liquor. The structure of the recovered material was determined by Fourier Transform Infrared Spectroscopy (FT-IR), Gel Permeation Chromatography (GPC) and Klason Component Analysis. Recycled lignin (RL) was used as the basis for the synthesis of a cationic recycled lignin-based polymers (CRLM) through graft polymerizing cationic monomer (DMC). The optimum synthesis conditions were obtained by conducting orthogonal experiments using the cationicity as the studied parameter, while selecting pH, DMC/RL, reaction temperature and time as independent variables. Recovery experiments showed that the maximum recovery concentration of RL in the black liquor was 5 g/L, with a purity of approximately 83 %. Orthogonal experiments showed that a low DMC/RL ratio was crucial for the synthesis of flocculants. When the molar ratio of DMC/RL was 3:1, the cationicity of the prepared CRLM was as high as 11.32 %. Zeta potential and decolorization experiments also confirmed the stable decolorization performance of CRLM in three kinds of anionic dye wastewater. The experimental results showed that charge neutralization, chemical bonding forces and auxiliary effects play great role to remove anionic dyes, resulting in 94 %, 89 % and 94.9 % removal against Reactive Red 195 (RR195), Acid Red 18 (AR18) and Direct 168 (DB168) respectively. Therefore, this study demonstrated the potential of using recycled waste lignin as synthesize lignin-based flocculants in the field of printing and dyeing wastewater by treating waste with waste.

Lignin-based covalent organic polymers with improved crystallinity for non-targeted analysis of chemical hazards in food samples

Lignin, the most abundant source of renewable aromatic compounds derived from natural lignocellulosic biomass, has great potential for various applications as green materials due to its abundant active groups. However, it is still challenging to quickly construct green polymers with a certain crystallinity by utilizing lignin as a building block. Herein, new green lignin-based covalent organic polymers (LIGOPD-COPs) were one-pot fabricated with water as the reaction solvent and natural lignin as the raw material. Furthermore, by using paraformaldehyde as a protector and modulator, the LIGOPD-COPs prepared under optimized conditions displayed better crystallinity than reported lignin-based polymers, demonstrating the feasibility of preparing lignin-based polymers with improved crystallinity. The improved crystallinity confers LIGOPD-COPs with enhanced application performance, which was demonstrated by their excellent performances in sample treatment of non-targeted food safety analysis. Under optimized conditions, phytochromes, the main interfering matrices, were almost completely removed from different phytochromes-rich vegetables by LIGOPD-COPs, accompanied by “full recovery” of 90 chemical hazards. Green, low-cost, and reusable properties, together with improved crystallinity, will accelerate the industrialization and marketization of lignin-based COPs, and promote their applications in many fields.

Closed-loop recycling of lignin-based sustainable polymers with an all-hydrocarbon backbone

Recyclable lignin-based polymers with an all-hydrocarbon backbone showing excellent thermal stability and mechanical properties are reported. These polyolefins can be depolymerized back to pristine monomers quantitatively under mild conditions.

Recent progress in sulfur-containing technical lignin-based polymer composites

Recent progress in sulfur-containing technical lignin-based polymer composites

Simple lignin-based, light-driven shape memory polymers with excellent mechanical properties and wide range of glass transition temperatures

Lignin is the most abundant biomass source of aromatic hydrocarbons but, at present, is not effectively utilized. The development of simple and efficient methods for producing lignin-based polymers to replace petroleum-based products is an important strategy for promoting environmentally friendly and sustainable materials and controlling carbon emissions. In this work, lignin-based, light-driven shape memory polymers (ELIDs) with improved mechanical properties have been prepared from enzymatic hydrolysis lignin, itaconic acid and 1,12-dodecanediol, without any chemical modification of the lignin. The polymers contain large proportions of lignin (20–40 wt%, designated ELID20 to ELID40) and their mechanical properties are dependent on the lignin content. Maximum tensile strength (46.9 MPa) was achieved with ELID30, maximum elongation at break (93.7 %) was achieved with ELID20 and highest fracture energy (10.75 J cm−3) was achieved with ELID25. These excellent mechanical properties are accompanied by good thermal stability and a wide range of glass transition temperatures (21.2–157.3 °C), supporting a broad range of applications. The shape fixation rate (Rf) and shape recovery rate (Rr) were highest for ELID30 (98.7 % and 97.4 %, respectively). Under 1 sun simulated solar irradiation, ELID20 reached a temperature exceeding the glass transition temperature in 15 s and, under 3 sun simulated solar irradiation, ELID30 reached a temperature of 130 °C and shape recovered in 60 s. The excellent mechanical properties and good light-driven shape memory of ELIDs provide inspiration for the development and utilization of lignin-based polymers.

THERMAL BEHAVIOR OF COATED BIO-POLYMERS

Thermal behavior in plastic materials has a strong influence on their performance. In the current research, scientists are using different equipment that highlights the calorimetric behavior of parts by the identification and localization of transitions and exothermic/endothermic reactions that take place during material heating. The paper aims to characterize from a thermal point of view a lignin-based polymer (Arboblend V2 Nature) coated with three distinct micro-ceramic powders: two based on chrome oxide - Cr2O3, Cr2O3 -xSiO2 -yTiO2 (commercial name Amdry 6420 and Metco 136F) and one based on zirconium oxide - ZrO2 18TiO2 10Y2O3 (commercially known as Metco 143). The samples to be covered were obtained by injection in the mold and the coating technique used was a thermal – APS (Atmospheric Plasma Spray). After thermal analysis, all three coated samples reviled thermal stability up to 230°C, the degradation of the lignin matrix taking place around 345°C. Thus, based on this important data the recommendation to be used in practical applications can be made. So, the Arbobelnd V2 Nature bio-polymer coated with ceramic micro-particles works in normal working parameters for temperatures not exceeding 200°C. The paper also highlights in the beginning part the systemic analysis of the coating process in order to underline the factors that significantly influence the output parameters as: structure, morphology, mechanical, tribological, and thermal behavior.

Enhanced flocculation of aluminum oxide particles by lignin-based flocculants in dual polymer systems

Lignin is an abundant phenolic polymer produced vastly in pulping processes that could be further valorized. In this work, anionic (AKLs) and cationic (CKLs) lignin-based polymers were made by polymerizing kraft lignin (KL) with acrylic acid (AA) or [2-(methacryloyloxy) ethyl] trimethyl-ammonium chloride (METAC), respectively. In the polymerization reactions, various molar ratios of AA or METAC to KL were applied to produce AKLs and CKLs with different characteristics. The produced AKLs and CKLs were used in single and dual systems to flocculate aluminum oxide in suspension. To assess the interaction of these lignin-based polymers with the aluminum oxide particles; the zeta potential, adsorption, and flocculation of the colloidal systems were evaluated comprehensively. The flocculation performance of the lignin-derived polymers was compared with that of the homopolymers of AA and METAC (PAA and PMETAC) and commercially used flocculants. In single polymer systems, among the anionic synthesized polymers and homopolymers, KL-A4 (an AKL) was the best flocculant for the aluminum oxide suspensions owing to its largest molecular weight (330 × 103 g/mol) and highest charge density (−4.2 mmol/g). Remarkably, when KL-A4 and KL-C4 (the CKL with the highest molecular weight and charge density) were used subsequently in a dual polymer system, a larger adsorbed mass and a more viscous adlayer were formed than those of single polymer systems on the surface of aluminum oxide particles. The synergy between KL-A4 and KL-C4 was even stronger than that between homopolymers, which led to more significant adsorption on the aluminum oxide surface and, consequently, more efficient flocculation, producing larger (22 μm) and stronger flocs, regardless of the agitation intensity used in the systems.

About Hydrophobicity of Lignin: A Review of Selected Chemical Methods for Lignin Valorisation in Biopolymer Production

Lignin is the second most abundant renewable natural polymer that occurs on Earth, and as such, it should be widely utilised by industries in a variety of applications. However, these applications and possible research seem to be limited or prevented by a variety of factors, mainly the high heterogeneity of lignin. Selective modifications of the structure and of functional groups allow better properties in material applications, whereas the separation of different qualitative lignin groups permits selective application in industry. This review is aimed at modification of the lignin structure, increasing the hydrophobicity of the produced materials, and focusing on several perspective modifications for industrial-scale production of lignin-based polymers, as well as challenges, opportunities, and other important factors to take into consideration.

Recent Studies on the Preparation and Application of Ionic Amphiphilic Lignin: A Comprehensive Review.

As the second most abundant natural polymer after cellulose, lignin has received considerable attention recently due to its reproducibility, safety, and biodegradability. Studies are now focusing on the development of new lignin applications to replace petroleum-based chemicals. Unfortunately, lignin has several inherent problems, such as poor water solubility and a tendency to agglomerate. However, after chemical modification, lignin can gain new functions through the introduction of new functional groups. For example, amphiphilic lignin is a polymer that is soluble in both water and organic solvents. Amphiphilic lignin polymers can be divided into anionic, cationic, and anionic-cationic amphoteric lignin-based polymers, according to the ions contained in their molecular structure. Amphiphilic lignin polymers also have a wide range of applications in various industrial fields and can be used as wetting agents, detergents, controlled release fertilizers, adsorbents, and emulsifiers. Thus, this article reviews research progress on the synthesis and applications of amphiphilic lignin-derived polymers over the past 10 years, providing a theoretical reference for the utilization of high-added-value and high-performance lignin.

Lignin as Green Filler in Polymer Composites: Development Methods, Characteristics, and Potential Applications

After cellulose, lignin is the most commonly used natural polymer in green biomaterials. Pulp and paper mills and emerging cellulosic biorefineries are the main sources of technical lignin. However, only 2–5% of lignin has been converted into biomaterials. Making lignin-based polymer biocomposites to replace petroleum-based composites has piqued the interest of many researchers worldwide due to the positive environmental impact of traditional composites over time. In composite development, lignin is being used as a filler in commercial polymers to improve biodegradability and possibly lower production costs. As a natural polymer, lignin may have different properties depending on the isolation method and source, affecting polymer-based composites. The application has been affected by the characteristics of lignin and the uniform distribution of lignin in polymers. The review’s goal was to provide an overview of technical lignin extraction, properties, and its potential appropriate utilization. It was also planned to revisit the lignin-based composites’ preparation procedure as well as their composite characteristics. Solvent casting and extrusion methods are used to fabricate lignin from polymeric matrices such as polypropylene, epoxy, polyvinyl alcohol, polylactic acid, starch, wood fiber, natural rubber, and chitosan. Packaging, biomedical materials, automotive, advanced biocomposites, flame retardant, and other applications for lignin-based composites has existed. As a result, the technology is still being refined to increase the performance of lignin-based biocomposites in several applications. This review could assist explain lignin’s position as a composite additive, which could lead to more efficient processing and application strategies.

A scalable and simple lignin-based polymer for ultra-efficient flocculation and sterilization

Current flocculation and sterilization are two separate steps that can cause environmental and economic problems. Lignin, an inedible industrial by-product, as raw material to prepare polymer that simultaneously realize flocculation and sterilization is of great significance for carbon neutral, sewage recycling, and economic benefit. However, the inherent defects of lignin such as heterogeneity, poor solubility and low reactivity cause difficulty in preparing and applying lignin-based polymers. Under this context, an energy-saving synergistic technology incorporating lignin refining and photoinitiated biphasic copolymerization system was pioneered, and an ultra-efficient dual-function lignin-based polymer with hyperbranched amphiphilic structure was successfully prepared, which contributed to 99.6% removal rate and distinguished sterilization effect for E. coli suspension at an ultra-low dose (4 mg/L and 10 mg/L, respectively). The purification mechanism indicated that the first flocculation was attributed to the synergy of charge attraction, bridging and sweeping, while the subsequent sterilization was achieved by blocking the metabolism and changing membrane permeability. The examination on various external influencing factors showed great adaptability of this lignin-based polymer to complex sewage environment with superiority over existing commercial products.

Preparation and Performance of Lignin-Based Multifunctional Superhydrophobic Coating.

Superhydrophobic coatings have drawn much attention in recent years for their widespread potential applications. However, there are challenges to find a simple and cost-effective approach to prepare superhydrophobic materials and coatings using natural polymer. Herein, we prepared a kraft lignin-based superhydrophobic powder via modifying kraft lignin through 1H, 1H, 2H, 2H-perfluorodecyl-triethoxysilane (PFDTES) substitution reaction, and constructed superhydrophobic coatings by direct spraying the suspended PFDTES-Lignin powder on different substrates, including glass, wood, metal and paper. The prepared lignin-based coatings have excellent repellency to water, with a water contact angle of 164.7°, as well as good friction resistance, acid resistance, alkali resistance, salt resistance properties and quite good self-cleaning performance. After 30 cycles of sand friction or being stayed in 2 mol/L HCl, 0.25 mol/L NaOH and 2 mol/L NaCl solution for 30 min, the coatings still retain super hydrophobic capability, with contact angles higher than 150°. The superhydrophobic performance of PFDTES-Lignin coatings is mainly attributed to the constructed high surface roughness and the low surface energy afforded by modified lignin. This lignin-based polymer coating is low-cost, scalable, and has huge potential application in different fields, providing a simple way for the value-added utilization of kraft lignin.